In the manufacture of socks, knee socks and hosiery it is often necessary for the items to be steamed in order to provide a foot shaped appearance to the article, or for providing ease during the packaging process. Steaming of such items can be conducted either manually or automatically by means of steaming forms, which hold the articles to be steamed. The steaming forms generally comprise two flat forms placed in parallel relationship with one another and have an anatomical correct profile, with each form comprising a foot portion and a heel portion. While a regular sock is generally axially asymmetrical, owing to the presence of the foot portion and the heel portion, a knee sock is different, and comprises a tubular shape which has a seam along a curve at one end. In both cases, the portion of the sock opposite the foot is typically called the band portion, which comprises an elastic fiber band; the foot and band portions are generally connected by a tubular knitted portion.
Generally, both types of sock have to be placed on the steaming forms such that they rest in the plane of the form and correspond to the shape of the form. In the case of regular socks, the foot typically fits the form and is stretched to reach a natural profile. However, in the case of knee socks, the form of the foot and of the heel portion of the sock is determined during the steaming step.
Regular socks or knee socks can be loaded on steaming forms either automatically or manually and both types of sock are generally placed on the steaming form starting from an unstretched condition. In the case of automatic loading, holding tools can be used so that the socks can be stretched transversally. Typically, a holding tool in an open position engages the steaming form to first place the foot of the sock on the form. The holding tool then moves translationally to progressively stretched the tubular portion of the sock along the form. Eventually, the sock is placed and stretched on the form and the band portion is released from the holding tool. After the sock has been stretched upon the form the holding tool releases the sock and exits the loading zone.
Shortly after the sock has been released from the holding tool, there is a tendency for the sock to unstretch due to the elasticity of the sock material. The sock, thus, tends to slide along the smooth surface of the steaming form. The unstretching of the sock to its pre-stretched configuration is undesirable and causes flawed steaming of both the tubular portion, and the band portion of the sock. Unstretching of the sock on the form can also cause an irregular sock profile, which can lead to problems during packaging.